The z4.zip file you have requested: Modifications / Cars / foreign / bmw / BMW Z4 Coupe - 2.24mb is not available. Perhaps try browsing all files for the game Need for Speed High Stakes and upload any files you want to share or are missing. This is the only information we could locate:
An addon model of a BMW Z4 Coupe for NFS: High Stakes. This is very similiar to the Z3 with different textures.